Press Release

Audentes Therapeutics Raises $65 Million In Series C Financing

Leading Healthcare Investors Provide Funding to Advance AAV Gene Therapy Pipeline in Serious, Rare Diseases to Key Clinical Milestones and to Build Internal Manufacturing Capabilities

SAN FRANCISCO, CA – October 13, 2015 – Audentes Therapeutics, Inc., a biotechnology company committed to the development and commercialization of gene therapy products for patients with serious, rare diseases, today announced the closing of an oversubscribed $65 million Series C financing. The financing was co-led by existing investor Sofinnova Ventures and new investor Redmile Group. Additional new investors include RA Capital Management, funds and accounts advised by T. Rowe Price Associates, Inc., Rock Springs Capital Management LP, Cormorant Asset Management LLC, Cowen Private Investments, and Foresite Capital. Existing investors OrbiMed, 5AM Ventures, Versant Ventures, Deerfield Management Company and Venrock also participated. The proceeds from the Series C financing will be primarily used to advance the company’s three lead development programs to key clinical milestones and to establish internal GMP manufacturing capabilities.

“We are very pleased to have many of the world’s leading healthcare investors participate in our Series C financing,” stated Matthew Patterson, President and Chief Executive Officer of Audentes Therapeutics. “This financing is a major step toward achieving our goal of bringing innovative and meaningful new treatments to patients suffering from life-threatening rare diseases.“

Cowen and Company served as exclusive placement agent for the financing.

About Audentes Therapeutics, Inc.

Audentes is a biotechnology company committed to the development and commercialization of innovative new treatments for people with serious, rare diseases through the application of AAV gene therapy technology. We have three products in development, AT001 for the treatment of X-Linked Myotubular Myopathy (XLMTM), AT002 for the treatment of Pompe disease, and AT003 for the treatment of the CASQ2 subtype of Catecholaminergic Polymorphic Ventricular Tachycardia (CASQ2-CPVT). Our team consists of focused, experienced, and passionate individuals committed to forging strong, global relationships with the patient, research, and medical communities.

For more information regarding Audentes, please visit us at www.audentestx.com.